1. Technical Field
The present invention relates to a heat sink which causes the heat generated by electronic components (e.g., semiconductors mounted on a substrate) to be dissipated and a mounting structure (e.g., an electronic component package) thereof.
2. Conventional Technique
As mounting structures of a semiconductor integrated circuit (hereinafter referred to as an “LSI” (Large Scale Integration)), there are available a structure in which a “QFP” (Quad Flat Package) or a “BGA” (Ball Grid Array) are used in which a silicon chip is built is mounted on a printed wiring board, and a flip chip mounting in which a bare LSI is mounted on a printed wiring board, etc. In all these cases, generally, a heat sink is mounted on an LSI which generates heat.
An example of a conventional mounting structure of a heat sink is described in Japanese Patent Laid-Open No. 10-275968 (Patent Document 1). In the mounting structure of a heat sink, the heat sink is placed on a top surface of an LSI mounted on a printed wiring board via a thermal conductive sheet, and this heat sink is fixed by being pushed against the LSI by a fixing member having spring properties. The heat sink has a bottom surface which is substantially flat, and a plurality of fins are formed on a surface opposite to the bottom surface.
Another example of a mounting structure of a heat sink is described in Japanese Patent Laid-Open No. 2001-85577 (Patent Document 2). In the mounting structure of a heat sink, slits of an arbitrary shape, such as Π-shaped slits (e.g., U-shaped slits), dual rectangular-shaped slits and H-shaped slits, are formed on a plate-like heat sink and flexibility is imparted to a portion where the heat sink is coupled to an LSI (a region which encloses an LSI to which the heat sink is to be connected and is called a “component adjoining region”). By selectively deforming the component adjoining region, the component adjoining region of the heat sink is brought into close contact with the top surface of the LSI in the mounting of a package of low thermal resistant T-BGA type.